Artificial tooth.



l. GOLDMAN.

ARTIFICIAL TOOTH.

' APPLICATION FILED AUG.23, 191s.

' 1,218,078. Patented Mar. 6,1917.

' FIQAQ Fl Q.1.

FIG 5 FIG 6 F'IQ 7 FIG 8 F|c..1o. F'|q.1i.

\h/l-rnlassas; FIVENTOR: v

- ISIDORE Quinn/v 19 TToR ISIDORE eoLnMAN, or LEEDS, ENGLAND.

ARTIFICIAL TOOTH.

Specification of Letters Patent.

- Patented Mar. 6, 1917.

Application filed August 23, 1916. Serial No. 116,524.

To all whom it mag concern:

Be it known that I, IsIDoRE GOLD-MAN, a subject of the Emperor of Russia, residing at Leeds, in the county of York, England, have invented a new and useful Improvement in Artificial Teeth, of which the following is a specification.

This invention relates tov an improved method of constructing artificial teeth.

Teeth for vulcanite dentures are known having a raised non-tapered rear boss with an internally screwed or undercut recess adapted to receive the vulcanite mass, and either with or without a pin or post embedded at one end in the body of the tooth and projecting outwardly through the recess.

Teeth of this type, that is to say, having the raised non-tapered boss and the internally screwed recess, have also been adapted for use with metallic dentures by filling the recess with a closely-fitting screwed metal plug, the tooth being subsequently fitted with a metal backing plate having an opening to disclose the plug and to enable said backing plate to be secured by soldering to the projecting end of the plug or of the plug and pin or post as the case may be.

Teeth for metallic dentures are also known having either a laterally rounded or a comparatively flat posterior face tapering toward the cervical border and having within said tapered posterior face a metal-lined longitudinal dovetailed groove or slot adapted to receive a closely-fitting metallic tongue, the posterior face of the tooth being subsequently fitted with a metal backing plate which is secured by soldering to a projecting lug or extension of the tongue.

Teeth of the flat-backed type, either for vulcanite or metallic dentures, are also known having a correspondingly flat metal backing plate to which the tooth is renewably attached either by cementing a grooved 0r undercut projection on the backing plate into an internally threaded recess in the tooth, or by cementing a conical pin on the backing plate'into a corresponding conical recess in the tooth, the projection or pin being formed integral with or attached permanently to the backing plate, and the metal backing plate in some cases having also a slightly overlapping lip to protect the cutting edge of the tooth.

My said invention consists more particularly in the combination of means hereinafter described and claimed whereby an artificial tooth may be firmly yet renewably secured to a metallic denture, and it is characterized (firstly) by the provision on the back of the porcelain tooth facing of a raised square (or rectangular) boss tapering not toward the cervical border but toward the cutting edge of the tooth and having an internally threaded (or otherwise undercut) central socket hole therein, and (secondly) by the provision of a metal backing having a correspondingly shaped recess adapted to receive the aforesaid raised and tapered boss on the porcelain facing and having also a centrally projecting threaded (or otherwise undercut) nipple, of substantially smaller diameter than the diameter of the socket hole, formed integral with or at tached permanently to said backing and adapted to project loosely and be cemented into the aforesaid socket hole in the porcelain facing, the loose fit of the nipple allowing of the cement being introduced into the annular-space between it and the walls of the socket hole.

Description of accompanying drawings.

Figure 1 is a rear elevation of a porcelain tooth facing in accordance with my invention.

Fig. 2 is a side elevation of the porcelain facing with the metal backing applied. Figs. 3 and flare sectional side elevations of the porcelain tooth facing and of the metal backingrespectively as illustrated in Fig. 2, showing more particularly the threaded form of socket hole and nipple.

Figs. 5 and 6 are sectional side elevations of the porcelain tooth facing and of the metal backing, but showing more particularly the equivalent undercut form of socket hole and nipple.

Figs. 7 and 8 are views similar to Figs. 5 and 6, but showing a slight modification designed to strengthen the cutting edge of the tooth.

Fig. 9 is a sectional side elevation of my invention as applied to a posterior tooth.

Fig. 10 is a rear elevation of a porcelain tooth facing illustrating the application of my invention to a comparatively long and narrow tooth.

Fig. 11 is a similar view illustrating the application to a comparatively short and wide tooth.

According to my said invention the porcelain facing A is constructed with a raised boss B on its rear surface, and embracing a part only of the width of said rear surface, which boss 13 is ordinarily square as shown in Fig. 1, but may (in the case of narrow or wide teeth) be rectangular as shown in Figs. 10 and 11. This boss B, having raised inclined edges both at top and bottom and also at the sides, tapers slightly toward the cut ting edge of the tooth as shown (the raised edge adjacent to the cutting edge being for this purpose formed of a lesser height than that toward the opposite end of the tooth), and is provided with a socket hole C formed centrally therein so as to extend into the body of the porcelain facing A. This socket hole C is either internally threaded as shown in Figs. 2 and 3, or for the same purpose is undercut for instance as shown in Figs. 5, 7, and 9.

The porcelain facing A is fitted to a metal backing D, which may be stamped, cast, or otherwise formed, having a square (or rectangular) recess E adapted to fit over the raised and tapered boss B on the porcelain facing, and having also a centrally projecting nipple F attached permanently to or formed integral with said backing, and substantially smaller in diameter than the socket hole G of the facing, adapted to fit loosely into said socket hole G, with an annular clearance space between the said nipple and the walls of the socket hole. This nipple F is either threaded as shown in Fig. 4, or for the same purpose is notched or undercut for instance as shown in'Figs. 6, 8, and 9. The porcelain facing A is thus adapted (by introducing cement into the aforesaid annular space) to be cemented firmly to the metal backing D, which may be attached to the plate or bridge by soldering or otherwise in the ordinary manner. This method of attachment has the important ad vantage that a broken tooth can be replaced at once without interfering in any way either with the metal backing D or with the plate or bridge to which the latter is attached.

If desired the cutting edge of the tooth may be strengthened (as shown in Figs. 7 and 8) by means of a small overlapping lip G on the outer edge of the metal backing D.

In the rectangular form of raised boss 13, as shown in Figs. 10 and 11, the central socket hole O and nipple F are made of a correspondingly elliptical form.

I claim:

Means for securing an artificial tooth to a metallic denture, comprising a tooth having a porcelain facing a raised rectangular boss (having raised edges both at top and bottom and also at the sides) on the back of the porcelain facing, tapering toward the cutting edge of the tooth and having an undercut central socket hole therein, in combination with a metal backing having a corresponding rectangular recess adapted to receive said boss and having also a projecting undercut nipple, of substantially smaller diameter than the diameter of said socket hole, permanently attached to said backing and adapted to project loosely and be cemented into said socket hole in the facing by cement introduced into the annular space between said nipple and the walls of said socket hole, said metal backing being adapted for attachment to the denture in the ordinary manner.

ISIlDORE GOLDMAN.

Witnesses:

JOHN E. WALsrr, ALLAN BENNETT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0. 

